What are the parameters when an aircraft is climbing?

Question

can you please define me those parameters.

thanks.

Answer 1

In a steady climb lift = weight.  

If lift > weight, then its climb rate is increasing.

If thrust > drag, then its forward speed is increasing.

Answer 2

a couple of petty paradoxes. (1) In a low-speed, high-power climb, lift is less than weight — because thrust is supporting part of the weight. It sounds crazy to say that lift is less than weight during climb, but it is technically true. (2) In a low-power, high-speed descent, lift is once again less than weight — because drag is supporting part of the weight.

These paradoxes are pure technicalities, consequences of the peculiar definitions of the four forces. They have no impact on pilot technique.

Although the main ideas go back to Galileo, we speak of Newton’s laws, because he generalized the ideas and codified the laws.

First Law

The first law of motion states: “A body at rest tends to remain at rest, while a body in motion tends to remain in motion in a straight line unless it is subjected to an outside force”. Although that may not sound like a very deep idea, it is one of the most revolutionary statements in the history of science. Before Galileo’s time, people omitted frictional forces from their calculations. They considered friction “natural” and ubiquitous, not requiring explanation; if an object continued in steady motion, the force required to overcome friction was the only thing that required explanation. Galileo and Newton changed the viewpoint. Absence of friction is now considered the “natural” state, and frictional forces must be explained and accounted for just like any others.

  Second Law

The second law of motion says that if there is any change in the velocity of an object, the force (Fu) is proportional to the mass (m) of the object, and proportional to the acceleration vector (a). In symbols,

Fu = m a              

The acceleration vector is defined to be the rate-of-change of velocity. See below for more about accelerations. Here Fu is the force exerted upon the object by its surroundings, not vice versa.

The following restatement of the second law is often useful: since momentum is defined to be mass times velocity, and since the mass is not supposed to be changing, we conclude that the force is equal to the rate-of-change of the momentum. To put it the other way, change in momentum is force times time.

  Third Law

The third law of motion expresses the idea that momentum can neither be created nor destroyed. It can flow from one region to an adjoining region, but the total momentum does not change in the process. This is called conservation of momentum. As a corollary, it implies that the total momentum of the world cannot change. Conservation of momentum is one of the most fundamental principles of physics, on a par with the conservation of energy .

In simple situations, the third law implies that if object A exerts a force on object B, then object B exerts an equal and oppositeforce on object A.

Note the contrast:

The third law says that if we add the force exerted by object A on object B plus the force exerted by object B on object A, the two forces add to zero. These are two forces acting on two different objects. They always balance.

Equilibrium means that if we add up all the forces exerted on object A by its surroundings, it all adds up to zero. These forces all act on the same object. They balance in equilibrium and not otherwise.

There is also a law of conservation of angular momentum. This is so closely related to conservation of ordinary linear momentum that some people incorporate it into the third law of motion. Other people leave it as a separate, unnumbered law of motion.

Two Notions of Acceleration

The quantity a = F/m that appears in equation 19.1 was carefully named the acceleration vector. Care was required, because there is another, conflicting notion of acceleration:

    * The scalar notion of acceleration generally means an increase in speed. It is the opposite of deceleration.

    * It is the rate-of-change of velocity. A forward acceleration increases speed. A rearward acceleration decreases speed, but it is still called an acceleration vector. A sideways acceleration leaves the speed unchanged, but it is still an acceleration vector, because it changes the direction of the velocity vector. There is no corresponding notion of deceleration, because any change in velocity is called an acceleration vector.

Alas, everyone uses both of these conflicting notions, usally calling both of them “the” acceleration. It is sometimes a struggle to figure out which meaning is intended. One thing is clear, though: the quantity a = F/m that appears in the second law of motion is a vector, namely the rate-of-change of velocity.

Do not confuse velocity with speed. Velocity is a vector, with magnitude and direction. Speed is the magnitude of the velocity vector. Speed is not a vector.

Suppose you are in a steady turn, and your copilot asks whether you are accelerating. It’s ambiguous. You are not speeding up, so no, there is no scalar acceleration. But the direction of the velocity vector is changing, so yes, there is a very significant vector acceleration, directed sideways toward the inside of the turn.

If you wish, you can think of the scalar acceleration as one component of the vector acceleration, namely the projection in the forward direction.

Try to avoid using ambiguous terms such as “the” acceleration. Suggestion: often it helps to say “speeding up” rather than talking about scalar acceleration.

Force is Not Motion

As simple as these laws are, they are widely misunderstood. For example, there is a widespread misconception that an airplane in a steady climb requires increased upward force and a steady descent requires reduced upward force.Remember, lift is a force, and any unbalanced force would cause an acceleration, not steady flight.

In unaccelerated flight (including steady climbs and steady descents), the upward forces (mainly lift) must balance the downward forces (mainly gravity). If the airplane had an unbalanced upward force, it would not climb at a steady rate — it would accelerate upwards with an ever-increasing vertical speed.

Of course, during the transition from level flight to a steady climb an unbalanced vertical force must be applied momentarily, but the force is rather small. A climb rate of 500 fpm corresponds to a vertical velocity component of only 5 knots, so there is not much momentum in the vertical direction. The kinetic energy of ordinary (non-aerobatic) vertical motion is negligible.

In any case, once a steady climb is established, all the forces are in balance.

Answer 3

The only parameter that makes an airplane climb:

Lift > Weight

Answer 4

more lift than weight

more thrust than drag